A. Field Of The Invention
The present invention relates to methods and containers for growing microscopic sized microorganisms and, in particular, to methods and structures for not only growing microbiological matter, but also microscopic viewing of the same without removal from the container.
B. Problems in the Art
Presently, the conventional way to grow microbiological organisms in a controlled and observable manner is to utilize such things as petri dishes, tissue culture flasks, tissue culture slide chambers, and fungus isolation bottles. These terms, and the associated structures defined by these terms, are well known in the art.
There are a variety of reasons for growing such organisms. Some examples include testing human tissue for the presence of unhealthy microorganisms, creating microorganisms for research, testing, or designated use, determining the presence of microbiological activity, etc.
Useful growth generally must be in these types of structures. It is not a trivial matter to generate growth. Such things as agar or other known in the art substances are used in the containers to instill a base or environment that is conducive to such growth. Also, the environment itself must be somewhat carefully controlled.
Another more subtle aspect is as follows. These structures and techniques are sometimes used to handle what might be considered dangerous microorganisms from a health risk standpoint. Thus, most of these structures are sealable from the external surroundings and allow for careful handling of these growths, and any airborne particles associated with the growth.
It is one matter to grow the microbiological activity. It is another matter to be able to detect the growth and identify it. These microorganisms are very small and generally require observation under microscopes to validate their identification.
Conventionally, the tasks of first growing the microorganisms and then viewing them under microscopes are done with two different structures. The petri dishes, tissue culture flasks, and fungus isolation bottles, represent structures to grow the items in the above discussed controlled manner. The prevailing view is that a substantial amount of agar or the like is required to stimulate valid and complete growth. Therefore, petri dishes and the like tend to be relatively large and deep, with a large access through a large cover or the like to allow introduction of agar, and then placement of a plurality of samples in various locations within the structure, such as the dish.
Examples of these types of structures can be found in the following U.S. Pat. Nos.:
______________________________________ U.S. PAT. NO. INVENTOR ______________________________________ 3,729,382 Shaffer, et al. 4,299,921 Youssef 5,134,064 Nordlund 4,668,633 Walton 4,280,002 Bailey, et al. 4,587,213 Malecki 4,280,000 Kozak, Jr. et al. 4,728,607 Dorn, et al. ______________________________________
A similar device that is specifically used to culture tissue samples is shown at:
______________________________________ U.S. PAT. NO. INVENTOR ______________________________________ 4,321,330 Baker, et al. ______________________________________
While these types of devices are generally considered by those in the art to be advantageous for growing microbiological activity, a distinct disadvantage is that they generally can not be utilized to also view the contents in situ under conventional light microscopes. The structures or containers are simply too large, and primarily too thick, to be positioned under and held in place by calibers of standard microscopes. Also, they generally are not conducive to good viewing because of their thickness, and the thickness of the agar or other growth medium in the container.
Microscope viewing of the growth inside these structures is therefore generally carried on as follows. The container is opened, and a portion of the growth is removed and placed onto a microscope slide. The slide is thin, transparent, and therefore allows precise viewing of the microbiological activity under conventional microscopes, as well as allows placement of the slide in the calibers.
Conventional laboratory microscope slides are well known in the art. Examples of more exotic types of structures for viewing in microscopes can be found in the following U.S. Pat. Nos.:
______________________________________ U. S. PAT. NO. INVENTOR ______________________________________ 4,790,640 Nason 4,271,270 Lukacsek 4,974,952 Focht ______________________________________
While such a system (growth in one container, microscope viewing by placing a sample on an microscope slide) is held by the state of the art to work adequately, problems, deficiencies, and room for improvements are submitted to yet exist with that process.
First, current practices, which utilize relatively thick, large amounts of agar as the growth medium, translate into relatively long amounts of time for growth to occur.
Second, once growth has occurred, the time consuming and cumbersome procedures of transferring a portion of the growth to a microscope slide (including all the preparation and handling that goes with this) must be done. Such a process must be done each time the cultured growth is checked.
Third, such handling introduces a level of disruption, destruction, and therefore uncertainty to the culture sample. No in situ microscopic viewing of the culture can take place.
A discussion of conventional techniques for microscoping examination of growth such as fungus is set forth at pages 180-181 of "Medically Important Fungi--A Guide to Identification" by Davise H. Larone (1987). At those pages, three types of microscopic examination techniques are set forth, first what is called a tease mount--which involves tearing a small portion of the growth from an agar surface and placing it in a drop off lactophenol cotton blue (LPCB) on a clean glass slide, covering that portion with the cover slip, and observing it under a microscope. It is a rapid method but is destructive and does not always preserve the original position and structure of the conidia, spores and the like; which are extremely important to allow accurate identification. The second method is called cellophane tape mount and is also rapid. It involves using the tape to remove part of the growth. The tape is then placed on a small drop of LPCB on a glass slide, sticky side down, and examined under a microscope. This method is better at retaining the original position of characteristic fungal structures. Third, what is called the slide culture technique is stated to be the best method for preserving and observing the actual structure of a fungus in a slide culture. Its disadvantages include that it is not rapid, it is described, however, as unsurpassed as a routine means of studying the fine points of microscopic morphology of fungi. The method includes suspending a microscopic slide in a petri dish with a 4 mm deep, 1.times.1 cm block of agar on top of the slide. The specimen is inoculated on the four sides of the agar block and a cover slip is placed over the block. Water is placed in the bottom of the dish and the specimen is incubated at room temperature. Fungus will ordinarily grow on the surface of the slide and under the surface of the cover slip. It is checked periodically and when growth is discovered, the cover slip is removed and placed in a drop of LPCB on a second slide. The agar block can also be removed from the first slide and a cover slip placed over that area. Both slides can then be viewed under a microscope.
It can therefore be seen that conventional examination techniques either sacrifice accuracy of identification for speed or speed for accuracy of identification. The most accurate method, the slide culture method, does not allow in situ viewing and is slow. It also utilizes a thick piece of agar.
There is, therefore, a need in the art for an improvement in this field. It is therefore a primary object of the present invention to provide a means and method for microbiological growth and in situ observation with microscopes which improves upon the state of the art.
Another object of the present invention is to provide an invention as above described which provides a growth chamber and the ability to view the chamber with a microscope, which is also flexible and versatile with respect to these procedures.
Another object of the present invention is to provide a means and method as above described which reduces the resources needed in these types of procedures in terms of time and effort.
A still further object of the present invention is to provide a means and method as above described which reduces the time needed to adequately grow the cultures to a point where they are useful.
Another object of the present invention is to provide a means and method as above described which reduces the time required to handle the cultures.
Another object of the present invention is to provide a means and method as above described which reduces the time required to identify the culture.
Another object of the present invention is to provide a means and method as above described which can eliminate laborious and time consuming tasks associated with such procedures.
A still further object of the present invention is to provide a means and method as above described which eliminates the need for or use of different structures and procedures for growth and observation of the cultures.
Another object of the present invention is to provide a means and method as above described which increases the accuracy and speed of growth and identification of cultures.
Another object of the present invention is to provide a means and method as above described which allows access to the culture without substantial disruption or destruction of the culture.
Another object of the present invention is to provide a means and method as above described which increases the number and type of procedures and options available to be performed on the culture.
Another object of the present invention is to provide a means and method as above described which increases the observability of the culture, for example, allowing in situ microscopic observation, in certain circumstances from more than one side, as well as allowing better non-microscopic observation.
A still further object of the present invention is to provide a means and method as above described which increases safety as to handling of such cultures.
Another object of the present invention is to provide a means and method as above described which simplifies and increases flexibility with respect to sub-culturing of cultures.
These and other objects, features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.